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Franck Pachot

RDBMS (vs. NoSQL) scales the algorithm before the hardware

By | AWS, NoSQL | No Comments

By Franck Pachot . In The myth of NoSQL (vs. RDBMS) “joins dont scale” I explained that joins actually scale very well with an O(logN) on the input tables size, thanks to B*Tree index access, and can even be bounded by hash partitioning with local index, like in DynamoDB single-table design. Jonathan Lewis added a comment that, given the name of the tables (USERS and ORDERS). we should expect an increasing number of rows returned…

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Franck Pachot

A lesson from NoSQL (vs. RDBMS): listen to your users

By | Database Administration & Monitoring, NoSQL | No Comments

By Franck Pachot . I have written a few blog posts about some NoSQL (vs. RDBMS) myths (“joins dont scale”, “agility: adding attributes” and “simpler API to bound resources”). And I’ll continue on other points that are claimed by some NoSQL vendors and are, in my opinion, misleading by lack of knowledge and facts about RDBMS databases. But here I’m sharing an opposite opinion: SQL being user-friendly is now a myth. Yes, that was the…

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Franck Pachot

The myth of NoSQL (vs. RDBMS) “a simpler API to bound resources”

By | NoSQL, Oracle | No Comments

By Franck Pachot . NoSQL provides an API that is much simpler than SQL. And one advantage of it is that users cannot exceed a defined amount of resources in one call. You can read this in Alex DeBrie article https://www.alexdebrie.com/posts/dynamodb-no-bad-queries/#relational-queries-are-unbounded which I take as a base for some of my “Myth of NoSQL vs RDBMS” posts because he explains very well how SQL and NoSQL are perceived by the users. But this idea of…

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Franck Pachot

A Serverless Standby Database called Oracle Autonomous Data Guard

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . Announced by Larry Ellison last week, here it is: the Autonomous Data Guard. You can try it, unfortunately not on the Free Tier. First you create an Autonomous Database (ATP or ADW) and then you enable Autonomous Data Guard. You know that “Autonomous” is the marketing brand for the services that automate a lot of things, sometimes based on features that are in Oracle Database for a long time. So let’s…

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Franck Pachot

DBPod – le podcast Bases de Données

By | AWS, Cloud, Database Administration & Monitoring, Database management, Development & Performance, DevOps, NoSQL, Oracle, Postgres, SQL Server | No Comments

By Franck Pachot . J’essaie quelque chose de nouveau. Je publie beaucoup en anglais (blog, articles, présentations) mais cette fois quelque chose de 100% francophone. En sortant du confinement, on reprend les transports (train, voiture,…) et c’est l’occasion de se détendre en musique mais aussi de s’informer avec des podcasts. J’ai l’impression que c’est un format qui a de l’avenir: moins contraignant que regarder une video ou ou lire un article ou une newsletter. Alors…

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Franck Pachot

19c: scalable Top-N queries without further hints to the query planner

By | Oracle | No Comments

By Franck Pachot . The FETCH FIRST … ROWS ONLY syntax arrived in Oracle 12c and is much more convenient than using a subquery with ‘ORDER BY’ wrapped in a “WHERE ROWNUM < …” around it. But as I mentioned in a previous post it required the FIRST_ROWS() hint to get correct estimations. In SQL you don’t want to overload your code for performance, right? The RDBMS optimizer does the job for you. This was…

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Franck Pachot

The myth of NoSQL (vs. RDBMS) “joins dont scale”

By | AWS, Database Administration & Monitoring, NoSQL, Oracle, Postgres, SQL Server | 13 Comments

By Franck Pachot . I’ll reference Alex DeBrie article “SQL, NoSQL, and Scale: How DynamoDB scales where relational databases don’t“, especially the paragraph about “Why relational databases don’t scale”. But I want to make clear that my post here is not against this article, but against a very common myth that even precedes NoSQL databases. Actually, I’m taking this article as reference because the author, in his website and book, has really good points about…

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Franck Pachot

Oracle ACFS: “du” vs. “df” and “acfsutil info”

By | Oracle | No Comments

By Franck Pachot . This is a demo about Oracle ACFS snapshots, and how to understand the used and free space, as displayed by “df”, when there are modifications in the base parent or the snapshot children. The important concept to understand is that, when you take a snapshot, any modification to the child or parent will [[email protected] ~]$ asmcmd lsdg DATAC1 State Type Rebal Sector Logical_Sector Block AU Total_MB Free_MB Req_mir_free_MB Usable_file_MB Offline_disks Voting_files…

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Franck Pachot

Oracle Autonomous Linux: cron’d ksplice and yum updates

By | Cloud, Database Administration & Monitoring, Oracle | No Comments

By Franck Pachot . Oracle Enterprise Linux (OEL) is a Linux distribution which is binary compatible with Red Hat Enterprise Linux (RHEL). However, unlike RHEL, OEL is open source, free to download, free to use, free to distribute, free to update and gets free bug fixes. And there are more frequent updates in OEL than in CentOS, the free base of RHEL. You can pay a subscription for additional support and features (like Ksplice or…

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Franck Pachot

The Oracle ACE program ♠ what it is not ♠

By | Database Administration & Monitoring | 4 Comments

By Franck Pachot . I had a few questions about the Oracle ACE program recently and I thought about putting some answers there. Of course, that’s only my point of view, there’s an official web page: https://www.oracle.com/technetwork/community/oracle-ace/index.html The program is flexible and open, with a large diversity of people, technologies, contributions, levels,… Then rather than explaining what it is, which would be limiting, I’ll rather tell you… what it is not. It is not a…

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